HOWTO: Approve just the #WSUS updates that are needed using #PoshWSUS and #PowerShell on a schedule

Recently we deployed a new “do-all, be-all” server (AD, WSUS, etc) to a small client with very poor bandwidth availability.  Just allowing WSUS to auto-approve every published update across all categories and all select products just wasn’t an option (and really shouldn’t be anyways) because it would have taken a month to download them over 3Mbps DSL.  So I wanted to only approve and download those updates that were needed, as opposed to WSUS built-in process of automatic approve everything in a classification or product then immediately trying to download it.

For a bit more background information, typically we configure WSUS at our smaller “hands off clients” to check for new updates at 4 am daily (although I’m considering switching to manual synchronization and using PowerShell to invoke the check on a schedule that is more “robost” shall we say.  This gives us about a day to vet the basic updates on our own production system (which is typically close in configuration to our smaller “hands off clients”) before the updates auto-approve after synchronization at the client locations.

In the past I have played with the native Windows Server Update Services PowerShell cmdlets, but lets be honest, they are only about half baked and certainly not ready for enterprise IT production (I’m really not sure what Microsoft was thinking).  The inability to auto-accept EULAs is bad.  Even worse is that if there is a EULA waiting to be accepted, Approve-WsusUpdate just pukes, exits, and refuses to acknowledge, and refuses to approve any other updates (even without EULAs on them).  So this means there really is no hands free way provided by Microsoft to auto-approve just the needed updates as they come out…

After some research, I settled on PoshWSUS.  In my honest opinion however, it is not well documented or supported (but it is good given the resources the author likely has at his disposal)…  It took me 4 hours of scouring Google and trial and error to come up with this basic script, which simply looks at all the needed updates and approves them, in the fewest lines of PowerShell possible.  In the end I had to mash together both the native WSUS PowerShell cmdlets and the PoshWSUS cmdlets to make this work, but it does work (so far anyways).

So, download from GitHub, drop it in C:\Windows\System32\WindowsPowerShell\v1.0\Modules and lets go…

First of all, we need to find just updates that are needed – err – rather **ALL** the updates that are needed.  I didn’t find a way in PoshWSUS to do this, but the native WSUS cmdlets let you do this.  Great – but you can’t pipe these updates (directly out of Get-WsusUpdate) into PoshWSUS’s Approve-PSWSUSUpdate, and I couldn’t find any way to get all needed updates out of Get-PSWSUSUpdate (which can pipe to Approve-PSWSUSUpdate), so I needed to get creative…  Get-PSWSUSUpdate, using a piped Where will allow you to select by the UpdateId, and Get-WsusUpdate will output UpdateId…  Hmmm….

Now – how to get the UpdateId from Get-WsusUpdate to Get-PSWSUSUpdate…  How about by piping the UpdateId via >> to a text file, then use foreach to read that text file into Get-PSWSUSUpdate, which then pipes to Approve-PSWSUSUpdate…  It’s ugly, it’s slow, but hey it works, and should only take a minute or two to run even on the heaviest of Patch Tuesdays…  And along the way, the text file needs cleaned up before being fed into Get-PSWSUSUpdate.

So here is the entire process (save this script as C:\Windows\WSUS_Updates_Approval.ps1)…

Import-Module PoshWSUS
$ThisComputersFQDN = "$env:computername"+"."+"$DNSDomainName"
Connect-PSWSUSServer -WsusServer $ThisComputersFQDN -Port 8530
$UpdateIDFile = "C:\Windows\Temp\UpdateIDFile.txt"
If (Test-Path $UpdateIDFile){Remove-Item $UpdateIDFile}
Get-WsusUpdate -Approval Unapproved -Status Needed | Select-Object UpdateId >> $UpdateIDFile
(Get-Content $UpdateIDFile| Select-Object -Skip 3) | Set-Content $UpdateIDFile
(Get-Content $UpdateIDFile| Foreach {$_.TrimEnd()}) | Set-Content $UpdateIDFile
$Groups = Get-PSWSUSGroup -Name 'All Computers'
foreach ($NewUpdateID in get-content $UpdateIDFile) {Get-PSWSUSUpdate | Where {$_.UpdateID -eq "$NewUpdateID"} | Approve-PSWSUSUpdate -Action Install -Group $Groups -Confirm:$false}

Finally, we just need to schedule this script to run on a regular basis… I typically schedule it to run every 15 minutes.  To do that, run this in an Administrative Command Prompt:

schtasks /create /tn "WSUS Updates Approval" /tr "\"C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe\" -ExecutionPolicy RemoteSigned -noprofile -File C:\Windows\WSUS_Updates_Approval.ps1" /sc minute /mo 15 /st 00:02:00  /rp "*" /ru "%userdomain%\%username%"

As always – Use any tips, tricks, or scripts I post at your own risk.

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